Planning for the weather is an important factor for making your trip to Nanjing County a success, especially when you're splurging. The hottest months are usually July and August with an average temp of 81°F, while the coldest months are January and December with an average of 59°F. The rainiest months in Nanjing County are June, August, May, and July, with each month seeing an average of 10 inches of rainfall.